Figure 7.

Scanning electron micrographs of electrospun PLGA nanofibers, (A) and (B), and their PPy-coated fibers, (C) and (D). (A) Randomly oriented nanofibers (RF), (B) aligned nanofibers (AF), (C) PPy-coated randomly oriented fibers (PPy–RF), and (D) PPy-coated aligned fibers (PPy–AF). SEM images of PC12 cells cultured on (E) PPy–RF and (F) PPy–AF for 2 days. (G) Median neurite lengths PC12 cells when unstimulated and when electrically stimulated (10 mV/cm) on random (PPy–RF) and aligned (PPy–AF) PPy–PLGA fibers. At least 300 neurites were analyzed from four substrates for each condition. Reproduced with permission.[137] Copyright 2009. SEM at 15,000_ magnification of NGF entrapped in PEDOT films compared with control films produced without NGF modification of the electrolyte (H) PEDOT/pTS, (I) PEDOT/DEDEDYFQRYLI, (J) PEDOT/DCDPGYIGSR, (K) PEDOT/pTS/NGF, (L) PEDOT/DEDEDYFQRYLI/NGF, (M) PEDOT/DCDPGYIGSR/NGF. (N) Electrochemical activity loss for NGF-loaded PEDOT films over 400 cycles of redox. Loss of electroactivity is plotted as a percentage of the original activity measured at cycle 1, normalising the polymers to a common baseline. The percentage activity remaining after 400 cycles is labeled. Error bars represent the standard error of the mean (n = 3). (O) Effect of NGF loading on ASTM hardness of PEDOT-based polymers. Gouge hardness is representative of a minor disruption to the polymer surface and scratch hardness depicts the level at which no polymer was removed from the Pt substrate. Error bars represent the standard error of the mean (n = 6). (P) Neurite outgrowth of PC12 cells on laminin peptide-doped PEDOT with NGF incorporation at 96 h post-plating. Neurite outgrowth is represented as the neurite length per adhered cell, calculated by normalising the total neurite length to the cell density. The standard error of the mean is given (n = 3). *No significant difference. Reproduced with permission.[49] Copyright 2010